Early settlers constructed permanent housing using logs cut from nearby wooded areas by notching and stacking the logs to form walls. Roofs were formed using log framing and sod covering. The chinks between the stacked logs were filled with indigenous clay mortar or sod.
Today, the construction of log homes relies on the use of close fitting timbers which have been cut and contoured to assure a chink-free wall, thus assuring an energy efficient structure having good insulating qualities due to the wood mass of the logs and the use of longer logs which do not require so many log junctures. This type of construction is utilized when the surrounding landscape requires the "woodsy" appearance of the house or cabin with the further benefit of protection against temperature extremes.
The prior art has attempted to provide various means to assist in the efficient construction of rough hewn structures in order to enable such structures to be erected on a competitive basis.
For example, Foster (U.S. Pat. No. 2,463,860) teaches a mount for portable chain saws having an elongated pointed drive arm which is driven into the log and supports a socket clamped thereto. A lateral support bar extends from the clamp socket and presents a number of annular grooves to guide the saw.
Hayden et al (U.S. Pat. No. 3,225,799) discloses a lumber sawing attachment for a portable chain saw assembly specifically directed toward cutting reclining logs lengthwise for conversion into elongated planks in remote locations.
Edmunson (U.S. Pat. No. 3,845,556) teach a cut control attachment for chain saws having a ripping dimension attachment together with angular adjustments in three planes. The attachment includes a sole plate attached to a chain saw guide bar, a ripping fence slideably and adjustably received by or attached to the sole plate for adjusting and setting a ripping width and an angle-adjustable guide bar yoke bracket with protractor on the sole plate for adjusting the cutting angle of the chain saw in one plane and an adjustable bracket bolt for adjusting the chain saw in a plane 90.degree. removed from the yoke bracket adjustment.
Jackson (U.S. Pat. No. 4,127,046) teaches a combination portable and stationary bench-mounted chain saw apparatus adapted to establish predetermined cut angles. The apparatus comprises a portable chain saw which includes a motor secured to one side of a flat mounting plate, a saw blade guide projecting from the motor through a slot in the mounting plate in a plane normal to the plane of the mounting plate. The saw blade extends around the guide plate and is protected by a guard means pivotally attached to the mounting plate. A cradle frame detachably secures the mounting plate in a table sawing position when the chain saw is to be so used. A pivotal cradle frame pedestal and a pivotal turntable is incorporated into the assembly.
Marshall (U.S. Pat. No. 4,208,937) teaches an apparatus for accurately cutting logs and large timbers at selected angles with a chain saw having a base framework from which a plurality of vertical rods extend. The bar of the chain saw is secured to guides which slide on the rods. The saw and the base frame-work are pivotally secured to a support table so that the saw blade can be positioned in a variety of angles relative to the object to be cut. Once a given angle is selected, the device is locked for repetitious use.
As indicated by the prior art, a number of devices have been proposed to notch and dimension timbers or logs. However, many of these prior art devices have been unsatisfactory because they are either of a fragile nature and/or require delicate and time-consuming adjustment. As the cutting operation is particularly important, portability to position the guide over long logs with great accuracy, which in turn allows the construction of tight and rigid corners or seams, is particularly important with regard to finished quality and economical construction costs. Of equal importance is the necessity to create a sawing jig that is structurally rigid and able to withstand the rigors of sawing and constant movement from log to log or timber to timber.